Treatment of sexual disorders in people with epilepsy

The impact of medications and medical comorbidities on sexual function in people with epilepsy

OBJECTIVE

People with epilepsy experience increased rates of sexual dysfunction, often affecting quality of life. Sexual dysfunction may result from the underlying disorder, antiseizure or other medications, or comorbid psychosocial factors. This study evaluated the incidence and clinical associations of sexual dysfunction in adult epilepsy patients.

METHODS

89 epilepsy patients 18 years and older admitted to the New York University Comprehensive Epilepsy Center epilepsy monitoring unit between 2016 and 2018 completed a survey on sexual functioning. The survey included demographic, clinical, and sexual functioning information with a validated measure of sexual function (the Arizona Sexual Experiences Scale (ASEX).

RESULTS

Of 89 surveys completed, 15 (16.9 %) patients had discussed sexual functioning with a medical professional and 20 (22.5 %) reported sexual dysfunction. For the group, the mean ASEX score was 13.6 (SD 4.8). 59 (66.3 %) participants reported not being asked about sexual health by their doctor or nurse practitioner in the last year. The two independent predictors of sexual dysfunction were self-identifying as overweight/obese (OR 6.1, CI 1.4-26.5, P = 0.02) or taking strong enzyme-inducing antiseizure medications (OR 7.8, CI 1.4-44.9, P = 0.02). Other factors such as age, relationship status, duration of epilepsy, the presence of depression or anxiety, cardiovascular risk factors, and opioid/stimulant use, did not predict sexual dysfunction.

SIGNIFICANCE

Our study showed that sexual dysfunction is common in epilepsy patients but infrequently discussed by medical professionals. Two modifiable risk factors, being overweight or taking strong enzyme-inducing antiseizure medications, were independently associated with sexual dysfunction, suggesting interventions to potentially improve sexual health.

Effect of Tadalafil on Seizure Threshold and Activity of Antiepileptic Drugs in Three Acute Seizure Tests in Mice

Tadalafil, a selective phosphodiesterase type 5 inhibitor, is a long-acting oral agent for the treatment of erectile dysfunction of multiple etiologies. Although generalized tonic-clonic seizures were reported in a healthy man after taking tadalafil, the influence of tadalafil on seizure susceptibility has not been studied so far. Therefore, the aim of the present study was to investigate the effect of tadalafil on seizure threshold as well as on the activity of some first- and second-generation antiepileptic drugs in three acute seizure tests in mice. The obtained results showed that tadalafil, at the highest dose tested (20 mg/kg), significantly decreased the threshold for the first myoclonic twitch in the intravenous pentylenetetrazole (i.v. PTZ) seizure test. It did not affect the threshold for generalized clonic seizure and forelimb tonus in the i.v. PTZ, for tonic hindlimb extension in the maximal electroshock seizure threshold test, and for psychomotor seizure in the 6-Hz-induced seizure threshold test. Tadalafil did not alter the anticonvulsant activity of any of the studied antiepileptic drugs in electrically induced seizure tests. Interestingly, tadalafil potentiated the anticonvulsant activity of clonazepam and decreased the anticonvulsant activity of oxcarbazepine in the i.v. PTZ test. These interactions were pharmacodynamic in nature, as tadalafil did not alter clonazepam and oxcarbazepine concentrations both in serum and brain tissue. Furthermore, neither tadalafil alone nor its combinations with the studied antiepileptic drugs produced any significant impairment of motor coordination (assessed in the chimney test), muscular strength (investigated in the grip-strength test), and long-term memory (assessed in the passive avoidance task). In conclusion, tadalafil may increase the risk of myoclonic seizure and decrease the anticonvulsant efficacy of oxcarbazepine. Further studies are warranted to evaluate the safety of tadalafil usage in patients with epilepsy.

The treatment of erectile dysfunction in patients with neurogenic disease

Erectile dysfunction (ED) related to compromise of the nervous system is an increasingly common occurrence. This may be due to the multifactorial nature of ED, the myriad of disorders affecting the neurotransmission of erectogenic signals, and improved awareness and diagnosis of ED. Nevertheless, neurogenic ED remains poorly understood and characterized. Disease related factors such as depression, decreased physical and mental function, the burden of chronic illness, and loss of independence may preclude sexual intimacy and lead to ED as well. The amount of data regarding treatment options in subpopulations of differing neurologic disorders remains scarce except for men with spinal cord injury. The treatment options including phosphodiesterase inhibitors, intracavernosal or intraurethral vasoactive agents, vacuum erection devices (VED) and penile prosthetic implantation remain constant. This review discusses the options in specific neurologic conditions, and briefly provides insight into new and future developments that may reshape the management of neurogenic ED.

Effect of sildenafil, a selective phosphodiesterase 5 inhibitor, on the anticonvulsant action of some antiepileptic drugs in the mouse 6-Hz psychomotor seizure model

Sildenafil, a selective phosphodiesterase 5 inhibitor (PDE5), has been recently reported to have both pro- and anticonvulsant action in various experimental models of seizures and epilepsy. Furthermore, it affects anticonvulsant action of some antiepileptic drugs (AEDs) in mice seizure tests and both pharmacodynamic and pharmacokinetic interactions were noted. The present study was carried out to investigate influence of sildenafil on the threshold for 6 Hz-induced psychomotor seizures in mice. Effect of sildenafil on activity of some AEDs, i.e., phenobarbital (PB), clonazepam (CZP), ethosuximide (ETS), valproic acid (VPA), tiagabine (TGB), oxcarbazepine (OXC) and levetiracetam (LEV), in 6 Hz test was also examined. Moreover, combination of sildenafil with LEV was investigated in terms of influence on motor coordination (determined by the chimney test), muscular strength (evaluated in the grip-strength test) and long-term memory (assessed in the passive avoidance task) in mice. To determine the type of pharmacological interaction between sildenafil and LEV, free plasma and total brain concentrations of this AED were determined by LC-MS/MS method. Sildenafil at a dose ranging from 10 to 40 mg/kg statistically increased psychomotor seizure threshold in mice. Moreover, sildenafil enhanced the anticonvulsant action of all the studied AEDs in this test. Interactions between this PDE5 inhibitor and PB, CZP, ETS, TGB and OXC seem to be pharmacodynamic. Since sildenafil increased free plasma and total brain concentration of LEV, interactions between these drugs have pharmacokinetic nature. This kind of interaction was also noted between sildenafil and VPA. Neither LEV (2.32 mg/kg) nor its co-administration with sildenafil (40 mg/kg) produced any significant changes in motor coordination, muscular strength and long-term memory in mice.

Sexual desire and satisfaction after resective surgery in patients with mesial temporal lobe epilepsy with hippocampal sclerosis

Utilizing a questionnaire, we inquired about the self-perceived sexual behavior of 50 married males with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) before and after anterior temporal lobectomy (ATL) and compared the results with those of 50 age-matched healthy married males. The sexual desire and satisfaction of the patients were poor when compared to the controls. Although a majority of the sexual domains improved following ATL, even after a median duration of five years, the sexual status of the patients did not match with that of the controls. Those who, after ATL, were seizure free, had one or no antiepileptic drug (AED) and had an EEG without epileptiform abnormalities achieved a better sexual outcome. We conclude that sexual dysfunction is frequent in male patients with MTLE-HS. They require preoperative assessment to identify their sexual inadequacies as well as counseling about the expected post-ATL sexual outcome. Discontinuation of enzyme-inducing AEDs facilitates post-ATL improvement in sexual function.

Sildenafil influences the anticonvulsant activity of vigabatrin and gabapentin in the timed pentylenetetrazole infusion test in mice

Sildenafil, a selective phosphodiesterase 5 (PDE5) inhibitor, has recently been reported to affect convulsant activity in some animal models of seizures and epilepsy. Moreover, its influence on the protective activity of some antiepileptic drugs (AEDs) was also noted. The aim of the present study was to investigate the effect of sildenafil on the anticonvulsant potential of gabapentin (GBP) and vigabatrin (VGB) in the timed intravenous (i.v.) pentylenetetrazole (PTZ) test in mice. The chimney test, the passive avoidance task and the grip strength test were used to estimate some possible side effects caused by the studied AEDs and their combinations with sildenafil. Total brain and free plasma concentrations of GBP and VGB were determined to evaluate the characteristics of interactions. Our studies revealed that GBP (25-100 mg/kg) increases the threshold for the forelimb tonic extension, whereas VGB raises thresholds both, for myoclonic (200-600 mg/kg) and generalized clonic (400-600 mg/kg) seizures in the used model of seizures. GBP at sub-effective dose of 12.5 mg/kg co-administered with sildenafil at doses of 10 and 20 mg/kg significantly increases the threshold for tonic seizures in the i.v. PTZ test in mice. Combination of sub-effective dose of VGB (200 mg/kg) with sildenafil at a dose of 5mg/kg also showed significant anticonvulsant activity against clonic seizures. The studied AEDs and their combinations with sildenafil did not produce any changes in the motor coordination, long-term memory and muscular strength in mice. Sildenafil did not influence total brain and free plasma concentrations of GBP and VGB. Interactions between the studied AEDs and sildenafil were pharmacodynamic in nature and for that reason they are worthy of consideration in the clinical practice.

Association between epilepsy and erectile dysfunction: evidence from a population-based study

INTRODUCTION

Although the association between epilepsy and sexual disorders has long been known, very few studies have attempted to explore the association between epilepsy and erectile dysfunction (ED).

AIM

This population-based case-control study aimed to investigate the association between ED and a prior diagnosis with epilepsy.

METHODS

This study used data from the Longitudinal Health Insurance Database 2000 in Taiwan. The cases comprised 6,427 patients with a diagnosis of ED and 32,135 controls who were frequency matched with cases based on 10-year age groups and index year. Conditional logistic regression was used to calculate the odds ratios (ORs) for prior epilepsy.

MAIN OUTCOME MEASURE

The prevalence and risk of epilepsy between cases and controls.

RESULTS

Of the sampled patients, 3,861 (14%) were diagnosed before the index date: 1,358 individuals (19.7%) were cases and 2,503 (12.1%) were controls. After adjusting for hypertension, diabetes, hyperlipidemia, renal disease, coronary heart disease, obesity, alcohol abuse/alcohol dependence syndrome, and socioeconomic status, conditional logistic regression analysis revealed that patients with ED were more likely to have been diagnosed with prior epilepsy than controls (OR = 1.83, 95% CI = 1.51-2.21). Compared with controls, the adjusted ORs for prior generalized epilepsy and partial epilepsy for cases were 2.13 (95% CI = 1.52-3.00) and 1.64 (95% CI = 1.31-2.06), respectively. The most pronounced associations were detected in ED cases aged between 30 and 39 who were 3.04 (95% CI = 1.67-5.50) times more likely than controls to have been previously diagnosed with epilepsy.

CONCLUSIONS

Our findings suggest a positive correlation between ED and a prior diagnosis with epilepsy.

Sexual quality of life in epilepsy: correlations with sex hormone blood levels

Seventy-nine consecutive inpatients of an epilepsy center (34 women, 45 men) who had either generalized epilepsy, temporal lobe epilepsy, focal epilepsy of other origin, or no epilepsy completed the Derogatis Interview for Sexual Function-Self-Report Inventory. Quantitative assessments of blood levels were performed for prolactin, total testosterone, sex hormone-binding globulin, estradiol, dehydroepiandrosterone sulfate, luteinizing hormone, and follicle-stimulating hormone. In men, increasing sex hormone-binding globulin levels and duration of epilepsy decreased sexual quality of life. Sex hormone-binding globulin level in men was related to enzyme-inducing antiepileptic drugs and age. In women, we found no associations between blood hormone levels and sexual quality of life. Our results suggest that sexual quality of life is affected by sexual hormone blood levels in men, but not in women with epilepsy. Avoiding enzyme-inducing antiepileptic drugs may lower the risk of raised sex hormone-binding globulin levels and, thus, of lowered sexual quality of life in men with epilepsy.

Aromatase inhibition, testosterone, and seizures

The effect of testosterone on brain excitability is unclear. The excitatory aspect of testosterone's action in the brain may be due to its conversion to estrogen via aromatase. We report herein a 61-year-old man with temporal lobe epilepsy and sexual dysfunction due to low testosterone levels. Use of an aromatase inhibitor, letrozole, normalized his testosterone level and improved his sexual functioning. Letrozole, in addition to standard antiseizure medication, was also associated with improved seizure control. This was sustained and, further, was associated with seizure exacerbation after withdrawing letrozole, and subsequent seizure improvement after restarting it. During the course of treatment, his serum testosterone level increased, sex hormone-binding globulin decreased (SHBG), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) levels increased, while serum estradiol levels remained undetectable. Letrozole may, therefore, have produced a central alteration in the testosterone/estrogen ratio, thereby impairing estrogen-mediated feedback control of the pituitary, resulting in the observed increase in circulating LH and FSH levels. This experience suggests that aromatase inhibitors should be further investigated as a beneficial treatment modality for male patients with epilepsy.